Researchers study infants for learning of language

PHILADELPHIA (AP) — Careful what you say. Baby’s listening.
Research into infants and language suggests that babies begin to pick up speech and can even tell apart different languages at a very early age. By 7 months, it seems, a baby can consistently tell the difference between some sound-alike words, such as “cut” and “cup.”
Psychologists described recent insights into baby talk Sunday at a meeting of the American Association for the Advancement of Science. They are trying to tease apart the milestones in learning speech, such as when babies can tell the cadence of one language from another, when they start to identify words in the babble of sound and when they begin to form these words into sentences.
Lila Gleitman of the University of Pennsylvania said that until about age 18 months, babies learn roughly one word every three days.
By the time they are a-year-and-a-half, babies begin to put together their first simple two-word sentences. And Gleitman said research suggests this acquisition of grammar is the key to rapidly learning new words.
From then on, Gleitman said, people typically learn 10 words a day, 3,500 or so words a year, until about age 30. After that, they continue to build their vocabularies, but the process slows, probably because most of the easy words have been learned. People typically level off at about 80,000 to 100,000 words.
However, she said there is little point into trying to cram vocabulary into very young children. They learn the basics of speech at about the same speed, no matter what their parents do.
Peter W. Jusczyk of Johns Hopkins University said his research suggests that infants begin to pick out individual words from sentences between 7 and 8 months of age. Further, they seem to be storing away words in memory at this age, building up a vocabulary, even when no particular effort has been made to teach them what words mean.